Single-channel control of a two-channel system

1979 ◽  
Vol 24 (3) ◽  
pp. 491-492 ◽  
Author(s):  
J. Potter ◽  
B. Anderson ◽  
A. Morse
Keyword(s):  
Single Channel ◽  
Channel System ◽  
Channel Control

Implementation of a single-channel active noise control system with multiple reference sensors

2020 ◽  
Vol 68 (5) ◽  
pp. 358-366
Author(s):  
H.E. Oh ◽  
W.B. Jeong ◽  
C. Hong
Keyword(s):  
Single Channel ◽  
Control Method ◽  
Reference Signal ◽  
Active Noise Control ◽  
Multiple Source ◽  
Weighted Sum ◽  
Reference Signals ◽  
Feedforward Controller ◽  
Channel Control ◽  
Source Signals

When multiple sources contribute competitively to the noise level, multi-channel control architecture is needed, leading to more cost and time for control computation. We, hence, are concerned with a single-channel control method with a single-reference signal obtained from a linear combination of the multiple source signals. First, we selected 3 source signal sensors for the reference signals and the error sensor, selected a proper actuator and designed the controllers: 3 cases of single-channel feedforward controllers with a single-reference signal respectively from the source signals, a multi-channel feedforward controller with the reference signals from the source signals, and the proposed controller with the reference signal from weighted sum of the source signals. The weighting factors and the filter coefficients of the controller were determined by the FxLMS algorithm. An experiment was then performed to confirm the effectiveness of the proposed method comparing the control performance with other methods for a tower air conditioner. The overall sound pressure level (SPL) detected by the error sensor is compared to evaluate their performance. The reduction in the overall SPL was obtained by 4.74 dB, 1.96 dB and 6.62 dB, respectively, when using each of the 3 reference signals. Also, the overall SPL was reduced by 7.12 dB when using the multi-reference controller and by 7.66 dB when using the proposed controller. Conclusively, under the multiple source contribution, a single-channel feed forward controller with the reference signal from a weighted sum of the source signals works well with lower cost than multi-channel feedforward controller.

Superposition properties of independent ion channels

1989 ◽  
Vol 238 (1291) ◽  
pp. 155-170 ◽  
Keyword(s):  
Ion Channels ◽  
Sojourn Time ◽  
Single Channel ◽  
Stochastic Modelling ◽  
Multiple Channels ◽  
Channel Activity ◽  
Channel System ◽  
Distributional Properties ◽  
Multichannel Systems ◽  
Selection Of

Membrane patches usually contain several ion channels of a given type. However, most of the stochastic modelling on which data analysis (in particular, estimation of kinetic constants) is currently based, relates to a single channel rather than to multiple channels. Attempts to circumvent this problem experimentally by recording under conditions where channel activity is low are restrictive and can introduce bias; moreover, possibly important information on how multichannel systems behave will be missed. We have extended existing theory to multichannel systems by applying results from point process theory to derive some distributional properties of the various types of sojourn time that occur when a given number of channels are open in a system containing a specified number of independent channels in equilibrium. Separate development of properties of a single channel and the superposition of several such independent channels simplifies the presentation of known results and extensions. To illustrate the general theory, particular attention is given to the types of sojourn time that occur in a two channel system; detailed expressions are presented for a selection of models, both Markov and non-Markov.

scholarly journals Dual-Channel Spectral Domain Optical Coherence Tomography Based on a Single Spectrometer Using Compressive Sensing

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 4006 ◽  
Author(s):  
Luying Yi ◽  
Liqun Sun ◽  
Mingli Zou ◽  
Bo Hou
Keyword(s):  
Optical Coherence Tomography ◽  
Compressive Sensing ◽  
Spectral Resolution ◽  
Single Channel ◽  
Optical Coherence ◽  
Channel System ◽  
Dual Channel ◽  
Imaging Depth ◽  
Imaging Speed ◽  
Sd Oct

Dual-channel spectral domain optical coherence tomography (SD-OCT) is one of the effective methods for improving imaging depth and imaging speed. In this paper, we design a dual-channel SD-OCT system based on a single spectrometer that can operate in two modes: (1) Increasing imaging speed and (2) expanding imaging depth. An optical path offset is preintroduced between the two channels to separate the two-channel data. However, this offset increases the requirement for the spectral resolution of the spectrometer in mode (1), so compressive sensing (CS) technology is used herein to overcome this problem. Consequently, in mode (1), when the spectral resolution of the spectrometer is the same as that used in the single-channel system, we use a dual-channel SD-OCT system combined with CS technology to double the imaging speed. In mode (2), when the spectral resolution of the spectrometer is only half of that used in a single-channel system, the imaging depth can be nearly doubled. We demonstrate the feasibility and effectiveness of the method proposed in this work by imaging a mirror, a fish fin, a fish eye, and an onion.

scholarly journals The Canadian Geophysical LBI System: Status and Future Plans

1991 ◽  
Vol 131 ◽  
pp. 453-456
Author(s):  
William T. Petrachenko ◽  
Pierre Mathieu ◽  
Joseph Popelar ◽  
Micheal Daniels
Keyword(s):  
Single Channel ◽  
Operational Efficiency ◽  
Prototype System ◽  
Channel System ◽  
Astronomical Data ◽  
Input Module ◽  
L Band ◽  
And Performance ◽  
Future Plans

AbstractEmphasis in the design of the Canadian Geophysical LBI (CGLBI) system has been placed on economy, operational efficiency, and performance in geophysical applications. Unique features of the system include the use of modified VHS recorders to store digitized astronomical data and the capability to track delay and fringe rotation during observation. A prototype system has been completed and tested at L-band using the ARO-DRAO interferometer baseline. The prototype system converts a single fixed 12 Mhz wide IF channel to baseband. Since delay resolution with this system is not sufficient for modern geophysical applications a frequency switching capability is being designed to synthesize a wide IF bandwidth while still maintaining the economy of a single channel system. Further improvements include the design of a phase cal detector and an input module compatible with NASA geodetic S/X receivers. Finally, efforts are being coordinated with ISTS so that record terminals developed for the Radioastron project can be interfaced to the CGLBI system.

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